Retention means for air cleaner element

ABSTRACT

The disclosure is directed to a centrifugal air cleaner which includes within an outer container a primary filter assembly and a secondary backup filter assembly, both of which are removably disposed for purposes of maintenance and replacement. The primary filter assembly is sealably held between the ends of the container. The secondary assembly is disposed within the primary assembly, but is independently supported at the filtered fluid outlet by a plurality of beaded spring clips which cooperate with an annular recess located on the inner wall of the outlet.

United States Patent Sullivan et a1.

[451 June 27, 1972 [54] RETENTION MEANS FOR AIR CLEANER ELEMENT [72]inventors: Bruce M. Sullivan, Burnsville; Carl M.

KIIIS, Bloomington, both of Mich.

Donaldson Company, Inc., Minneapolis, Min,

22 Filed: April 2,1970

211 Appl. No.: 25,092

[73] Assignee:

[52] US. Cl ..55/323, 55/330, 55/333, 55/337, 55/432, 55/449, 55/457,55/481, 55/487, 55/498, 55/502, 55/504, 55/507, 55/509, 55/510,

55/D1G. 28 [51] Int. Cl ..B0ld 59/50 [58] Field ofSearch ....55/337,428,432-433,

[56] Relerences Cited UNITED STATES PATENTS 1,107,485 8/1914 Bowser..55/337 UX 940,142 1 H1909 Fogarty. ..55/486 X 2,921,777 1/1960 Hepp55/509 UX 3,201,927 8/1965 Wachter.... ..55/504 751,918 2/1904 Jagger..210/448 2,647,636 8/1953 Rafierty 210/448 X 3,429,108 2/1969 Larson55/337 X 2,979,159 4/1961 Pritchard et a1. ..55/482 3,494,114 2/1970Nelson et a1. 55/482 3,174,775 3/1965 Clayton ..55/507 FORElGN PATENTSOR APPLlCATlONS 913,261 7/1949 Germany ..55/505 906,638 3/1944 France....55/481 926,901 4/1955 Germany .55/503 Primary Examiner-Dennis E.Talbert, .lr. Assistant Examiner-Vincent Gifford AnorneyMerchant & GouldABSTRACT The disclosure is directed to a centrifugal air cleaner whichincludes within an outer container a primary filter assembly and asecondary backup filter assembly, both of which are removably disposedfor purposes of maintenance and replacement. The primary filter assemblyis sealably held between the ends of the container. The secondaryassembly is disposed within the primary assembly, but is independentlysupported at the filtered fluid outlet by a plurality of beaded springclips which cooperate with an annular recess located on the inner wallof the outlet.

5 Claims, 5 Drawing Figures PATENTEnJuxzv r912 3,672,130

sum 2 or 2 l p/0H A R T INVENTORS. z/BRUCE JVI'. SULLIVAN CARL M KAUSATTORNEYS RETENTION MEANS FOR AIR CLEANER ELEMENT The invention isdirected generally to the field of air cleaners used with internalcombustion engines, and specifically to centrifugal air cleaners thatare particularly efficient in removing dust and dirt.

Under conditions where dust and dirt prevail in surrounding air, it isextremely important that air cleaners having adequate dust removalcapability be used to enable continuous satisfactory performance ofinternal combustion engines. The centrifugal air cleaner has been foundto perform this function very efficiently, although systematicinspection and maintenance of the air filter assembly are a necessity.

U.S. Pat. No. 3,078,650, issued to Dale K. Anderson and William R. Wolffon Feb. 26, [963, discloses and claims such a centrifugal air cleaner.In this type of device, an annular air filter assembly is inserted intoa cylindrical outer container and forms an annular air passagetherewith. Unfiltered air is taken in through an inlet at one end of theannular passage, and is caused to swirl or fiow spirally to the oppositeend of the passage. The swirling air fiow causes dust and dirt particlesbrought in with the unfiltered air to be centrifugally forced againstthe outer container, and they are collected and removed through a dustoutlet disposed at the opposite end of the passage. An air imperviousbaffle encircles a portion of the air filter assembly at the oppositeend of the annular passage to prevent the collected dust and dirtparticles from passing into the adjacent air filtering material.

Air in the annular passage is drawn radially inwardly by the pressuredifferential created by the internal combustion engine, and flowsthrough a passage formed in the center of the air filter assembly to thecarburetion system.

Because continuous filtration of dust and dirt is necessary to preventdamage to the engine, it has become the practice to include a secondaryfilter assembly of somewhat less filtering capability to providefiltration in case of breakage or damage to the primary element. Undernormal operation, the secondary element does little filtering and causesan insignificant pressure drop since the primary element carries thefiltering load. With breakage or damage to the primary, however, thesecondary element has sufficient filtering capacity to enable safeoperation of the engine for a period of time.

Although the secondary filter assembly provides backup filtration, itsincorporation into the air cleaner has presented problems. For instance,the prevalent method of supporting and retaining secondary filterelements in centrifugal air cleaners has been through the use of anA-frame yoke to which the element is fastened. Obviously, including theyoke in an air filter container is more difficult to manufacture andtherefore more expensive to produce. Further, it adds cost to allcontainers whether or not the secondary filter element is used.Fastening and unfastening the filter element for purposes of maintenanceand replacement has also been found to be both time consuming and highlyinconvenient.

Our invention is the result of an endeavor to solve these problems. Theinventive combination accomplishes this through the use of a secondaryfilter element that is disposed within the primary element, but isindependently supported in cantilever fashion by inserting it into theoutlet tube of the air cleaner housing. The secondary element is held inplace through formation of an annular groove on the inner face of theoutlet tube, and providing the supporting end of the secondary elementwith a plurality of beaded spring clips which are received by theannular groove. The secondary filter assembly also includes an annularcollar at the supporting end which cooperates with an associated end ofthe air cleaner housing to provide a seal.

In addition to solving the problems stated above, the inventivecombination permits the primary filter element to be removed withoutaffecting the sealed condition of the secondary element. Further, theonly change made to the air cleaner housing is provision of the annulargroove on the inner face of the outlet tube. Thus, the additional costof an air cleaner using a secondary filter element is in the secondaryelement itself. Because of the unique method of supporting and retainingthe secondary element, maintenance and replacement are a simple matter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a centrifugalair cleaner embodying the inventive principle, part thereof being brokenaway;

FIG. 2 is an end view of the centrifitgsl air cleaner;

FIG. 3 is a side view of a safety filter element adapted for use in thecentrifugal air cleaner, portions thereof being broken away;

FIG. 4 is an enlarged fragmentary end view of the centrifugal aircleaner with the safety filter element properly inserted; and

FIG. 5 is a side view ofa centrifugal air cleaner illustrating a priorart supporting structure for a safety filter element, part thereof beingbroken away.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 5 is referred to initiallyfor the purpose of illustrating a centrifugal air cleaner employingconventional structure for supporting and retaining a secondary filterelement. The centrifugal air cleaner is represented generally by numeral1 l and consists of a cylindrical outer container 12 which housesconcentric primary and secondary filter elements 13 and 14,respectively. Outer container 12 has an air inlet 15 which receives anddktributes unfiltered air to an annular space 16 which is defined by theinner face of container 12 and the outer face of primary element l3. Aplurality of fins 17 (only one of which is shown) carried by an airimpervious cylindrical baflle 30 are disposed adjacent inlet l5 to causethe im coming air to flow in a spiral fashion through space 16.

A dust collecting amembly I8 is constructed to sealably clone the openleft end of container 12. Assembly 18 consists of an outer shell 19, anoutlet 20 projecting radially outward from shell 19 with a dust cup 21mounted thereon, and a baffle plate 22 which a carried by a screw 23,collar 24 and wing nut 25.

Shell 19 has a radius chosen to telescopically fit over the open leftend of container 12, and is receivably retained by a clamping band 26.The radius of baffle plate 22 is chosen to telescopically fit over thelefi end of primary element l3 when positioned properly.

The right end of container 12 terminates in a filtered air outlet 27.Alfixed to the inner face of outlet 27 is a frame 28 which takes thegeneral form of an A-frame. Projecting from the end frame 28 is a screw29 which supports and retains the left end of both primary element 13and secondary element 14. The right end of secondary filter element 14is open to fit over frame 28 and sealably engage the right end ofcontainer 12 through a gasket member 3|. Similarly, primary filterelement 13 is open at its right end and sealably engages a sealingmember 32 at the right end of container 12. Both elements l3, 14 areclosed at their left ends and include apertures for receiving screw 29upon proper placement over frame 28. Wing nuts 33, 34 secure filterelements l3, 14 respectively, to frame 28.

In operation, unfiltered air is taken in through inlet 15 and caused toswirl or spirally flow through annular space l6 by fins l7. Sleeve 30assists in the generation of a swirling flow by preventing radiallyinward filtration of air through the right end of primary element 13.This spiral air flow imparts centrifugal force to any dust, dirt orother impure particles brought into inlet 15 driving them radiallyoutward along annular space 16 until they are collected in the dustcollecting assembly 18 and exhausted by dust cup 21. Battle plate 22prevents the dust and dirt particles from entering primary filterelement 13 after having been collected in assembly [8.

While the dirt and dust particles are driven outward by centril'ugalforce, the air flowing spirally in annular space 16 is drawn inwardlythrough primary filter element 13 by a pulsating pressure differentialcreated by operation of the internal combustion engine. The air isfiltered as it passes through element l3, and continues throughsecondary filter element 14, outlet 27 and on to the carburetion systemintake of the engme.

In order to remove either of the filter elements 13, 14 for routineinspection, maintenance or replacement, it is first necessary to removeclamping band 26 and dust collecting as sembly l8. Wing nut 33 can thenbe removed from screw 29 for removal of primary element 13, and wing nut34 is then unscrewed to permit removal of secondary element I4.Reinsertion of elements I3, 14 is in the reverse manner, making surethat the open right ends of each properly engages gasket ele ments 31,32 respectively.

FIGS. 1 and 2 disclose an improved centrifugal air cleaner 41. Aircleaner 41 also includes an outer container 42 which houses a primaryfilter element 43 and a secondary filter element 44. An air inlet 45communicates with an annular passage 46 defined by the inner face ofcontainer 42 and the outer face of primary filter element 43. Aircleaner 41 has a first outlet 47 communicating directly with annularpassage 46 and a second outlet 48 for the filtered air. A dust cup 49 isused with outlet 47 as hereinabove described.

As best seen in FIG. 1, the open right end of container 42 is rolled toprovide a smooth peripheral edge.

Primary filter element 43 is cylindrical in shape, one end being closedby a plate 51 with the opposite end open. Primary element 43 isremovably supported within container 42 in a conventional fashion byfirst fitting the closed end with a resilient sleeve 52 having anoutwardly projecting flange 53 and an inwardly projecting flange 54 forproperly positioning sleeve 52 on element 43. Element 43 is insertedinto the open end of container 42 so that the left end sealably engagescontainer 42 by means of a gasket 55, with sleeve 52 and the flange 53sealably engaging the rolled edge. Element 43 is held in position by aclamping member 56 (see also FIG. 2), which has a pair of extendingbiasing arms which receive support from a pair of cars 57, 58 mounted oncontainer 42. Between the extended biasing arms of clamping member 56 isa camming surface 59 which can be rotated into a spring-biasedengagement within cap 51 of element 43. The extended biasing armassociated with car 57 is looped so that in the disengaged positionclamping member 56 can be swung out and away to enable removal ofprimary element 43 from container 42.

Referring additionally to FIG. 3, secondary filter element 44 is similarto element 43, consisting of inner and outer perforated shells 61 and62, respectively, with filtering material 63 disposed therebetween. Oneend of element 44 is open, while the other is closed with an end cap 64.Element 44 differs from element 43 by being smaller in size and havingfiltering material of somewhat less filtering capacity in order that thealready filtered air does not undergo another significant pressure drop.

As best seen in FIG. 1, the inside diameter of outlet 48 is slightlygreater than the outer diameter of perforated shell 61 to enable it toreceive and support secondary element 44. The inner face of outlet 48 isformed with an annular recess or groove 65 that assists in thissupporting function, as described below.

As seen in FIG. 3, a cylindrical sleeve 66 having an outtumed flange 67is affixed to outer perforated shell 61 ad jacent the open end of filterelement 44. Sleeve 66 carries a plurality of spring clips 68, each ofwhich projects toward the open end of filter element 44 and includes araised or beaded portion 69 which is sized to fit into the annulargroove 65 in outlet 48. The clips 68 frictionally fit over flange 67 andare held in place by a resilient gasket member 71 having an annulargroove which also enables it to snugly fit over flange 67. Thus, withprimary filter element 43 removed, secondary filter element 44 can beplaced in air cleaner 41 by inserting its open end into outlet 48 untilthe raised portion 69 of each clip 68 is received by annular groove 65.See FIG. 4. This not only supports and locks filter element 44 in place,but also causes gasket member 7 l to engage the end of container 42 toform a seal therewith. Hence, should the primary element 43 of a fullyassembled air cleaner 41 become defective, the secondary element 44provides a sufficient filtering function until primary element 43 can bereplaced.

The inventive combination enables both the primary and secondary filterelements to be inspected, serviced or replaced more quickly andefliciently than in the prior art device. Moreover, the onlymodification to a prior art container hav ing a primary filter elementas shown in FIGS. 1 and 2 is formation of the annular groove 65 inoutlet 48. The only change in secondary filter element 44 over thatshown in FIG. I is the addition of sleeve 66 and clips 68. Consequently,the resulting combination offers firm support to secondary element 44while substantially reducing manufacturing costs and improving the easeof assembly and disassembly in the field.

What is claimed is:

l. A centrifugal fluid cleaner comprising:

a. an outer container having first and second ends;

b. a primary fluid filter assembly having first and second ends with afirst fluid passage formed therethrough, the primary filter assemblyremovably supported in the outer container and forming a second fluidpassage therewith;

c. fluid inlet means communicating with one end of the second passagefor receiving unfiltered fluid;

d. a first outlet communicating with the opposite end of the secondpassage for receiving and exhausting impure particles;

e. a second outlet for receiving and conducting filtered fluid from thefluid cleaner, comprising 1. an opening formed in the first end oftheouter container;

2. and a fluid conducting outlet member of predetermined size and shapecommunicating with the opening and projecting outwardly therefrom, thefluid conducting member having an inner face in which a groove isformed;

f. fluid control means for effecting a spiral fluid flow in the secondpassage between the inlet means and the first outlet, thereby impartingcentrifugal force to impure particles in the second fluid passage;

g. and a secondary fluid filter assembly having first and second endswith a third fluid passage formed therethrough, the second end beingclosed;

h. the first end of the secondary filter assembly being sealablyinsertable into said outlet member, and removably supported independentof the first filter assembly by supporting means comprising l. aplurality of spring clips affixed to the first end of the secondaryfilter assembly, each clip having a ridge portion receivable in saidgroove in spring-biased relation therewith upon insertion of said firstend of the secondary filter assembly into said outlet member.

2. The apparatus as defined by claim 1, wherein the outlet member andthe first end of the second fluid filter assembly are cylindrical inshape.

3. The apparatus as defined by claim 1 and further comprismg:

a. a sleeve member constructed to fit over the first end of thesecondary filter assembly and having an outturned flange spacedtherefrom;

b. each of the spring clips being carried by the flange and projectingtoward the first end;

c. and a resilient sealing member encircling the flange and carriedthereby, the sealing member constructed and arranged to sealably engagethe first end of the outer container upon insertion of the secondaryfluid filter assembly into the outlet member.

4. A replaceable filter assembly for a centrifugal fluid cleaner havinga fluid inlet, a first fluid outlet for centrifuged impure particles,and a second outlet for the filtered fluid defined by a projectingoutlet member of predetermined size and shape and having an inner facewith a groove formed therein, the filter assembly comprising:

a. an elongated filter cartridge having a first end sized forinspring-biased relation therewith upon insertion of the sertion intothe outlet member. a second end and a lonfilter assembly into the outletmember; gimdina] W S formed therein betwwn the first and d. and asealing member mounted on the flange to sealably seccmd engage thecentrifugal air cleaner adjacent the second b. a sleeve memherconstructed to fit over the filter car- 5 outlet and thereby prevent thepassage of unfiltered air Edge and having an outturned flange spacedfrom the therefrom rs en 5. The apparatus as defined by claim 4, whereinthe filter c. a plurality of spring clips earned by the flange andprocartridge is cylindrical jecting toward the first end of thecartridge, each clip having a ridge portion adapted to be received inthe groove in IO

1. A centrifugal fluid cleaner comprising: a. an outer container havingfirst and second ends; b. a primary fluid filter assembly having firstand second ends with a first fluid passage formed therethrough, theprimary filter assembly removably supported in the outer container andforming a second fluid passage therewith; c. fluid inlet meanscommunicating with one end of the second passage for receivingunfiltered fluid; d. a first outlet communicating with the opposite endof the second passage for receiving and exhausting impure particles; e.a second outlet for receiving and conducting filtered fluid from thefluid cleaner, comprising
 1. an opening formed in the first end of theouter container;
 2. and a fluid conducting outlet member ofpredetermined size and shape communicating with the opening andprojecting outwarDly therefrom, the fluid conducting member having aninner face in which a groove is formed; f. fluid control means foreffecting a spiral fluid flow in the second passage between the inletmeans and the first outlet, thereby imparting centrifugal force toimpure particles in the second fluid passage; g. and a secondary fluidfilter assembly having first and second ends with a third fluid passageformed therethrough, the second end being closed; h. the first end ofthe secondary filter assembly being sealably insertable into said outletmember, and removably supported independent of the first filter assemblyby supporting means comprising
 1. a plurality of spring clips affixed tothe first end of the secondary filter assembly, each clip having a ridgeportion receivable in said groove in spring-biased relation therewithupon insertion of said first end of the secondary filter assembly intosaid outlet member.
 2. and a fluid conducting outlet member ofpredetermined size and shape communicating with the opening andprojecting outwarDly therefrom, the fluid conducting member having aninner face in which a groove is formed; f. fluid control means foreffecting a spiral fluid flow in the second passage between the inletmeans and the first outlet, thereby imparting centrifugal force toimpure particles in the second fluid passage; g. and a secondary fluidfilter assembly having first and second ends with a third fluid passageformed therethrough, the second end being closed; h. the first end ofthe secondary filter assembly being sealably insertable into said outletmember, and removably supported independent of the first filter assemblyby supporting means comprising
 2. The apparatus as defined by claim 1,wherein the outlet member and the first end of the second fluid filterassembly are cylindrical in shape.
 3. The apparatus as defined by claim1 and further comprising: a. a sleeve member constructed to fit over thefirst end of the secondary filter assembly and having an outturnedflange spaced therefrom; b. each of the spring clips being carried bythe flange and projecting toward the first end; c. and a resilientsealing member encircling the flange and carried thereby, the sealingmember constructed and arranged to sealably engage the first end of theouter container upon insertion of the secondary fluid filter assemblyinto the outlet member.
 4. A replaceable filter assembly for acentrifugal fluid cleaner having a fluid inlet, a first fluid outlet forcentrifuged impure particles, and a second outlet for the filtered fluiddefined by a projecting outlet member of predetermined size and shapeand having an inner face with a groove formed therein, the filterassembly comprising: a. an elongated filter cartridge having a first endsized for insertion into the outlet member, a second end and alongitudinal passage formed therein between the first and second ends;b. a sleeve member constructed to fit over the filter cartridge andhaving an outturned flange spaced from the first end; c. a plurality ofspring clips carried by the flange and projecting toward the first endof the cartridge, each clip having a ridge portion adapted to bereceived in the groove in spring-biased relation therewith uponinsertion of the filter assembly into the outlet member; d. and asealing member mounted on the flange to sealably engage the centrifugalair cleaner adjacent the second outlet and thereby prevent the passageof unfiltered air therefrom.
 5. The apparatus as defined by claim 4,wherein the filter cartridge is cylindrical.